For the past year, we have attempted to characterize various facets of cognitive abnormalities in schizophrenia. In particular, we have tried to examine underlying cognitive mechanisms that might produce certain clinical features of the illness. 1. In general, our work suggests that thought disorder may be due to abnormalities in semantic organization in schizophrenia. We have not found that thought disorder is related to working memory or executive dysfunction. Rather, we have observed that thought disorder may be related to negative priming on tasks necessitating "spreading semantic activation". Also, we have found that thought disorder may be related to differential impairment in semantic rather than phonologic fluency. 2. We have examined working memory in a variety of paradigms. First, we showed that short term memory deficits were due to "cognitive capacity limitations" rather than attention or distractibility per se. We also showed that deficits on a task of short term memory in the face of interference may be due to some combination of differences in both delayed time and actual amount of information that must be remembered. Third, we showed that working memory was an important component. 3. By examining a variety of neuroleptics including risperidone, clozapine and haloperidol, we observed a double-dissociation. Clozapine might have been official effects on attention of vigilance, but may have deleterious effects on working memory and secondary memory. These results may be understood on the basis of clozapine's relatively benign effect on basal ganglia function and its possible adverse affect on dopamine mediated and cholinergic mediated cortical cognitive functioning. 4. We have continued to assess the specificity of cognitive impairment in schizophrenia by examining patients with traumatic brain injury. 5. We again have looked at the issue of subtyping in schizophrenia. In particular, we found no differences between male and female patients. 6. We have examined secondary memory. We were interested in examining whether schizophrenic patients performed differently on ecological memory tasks then laboratory memory tasks with and without reward. We also were interested in conditions under which schizophrenic patients might confabulate given their tendency to maintain bizarre delusions.